I'm sure this is a dumb question and I just haven't come across the explanation in my own yet; but I'll put it out there anyhow - in French, how does one ever know if someone is intending to say "I used to do ..." or their intent is to say "I did..."? These are quite different things, yet are said the same in french?

What is confusing is that "used to think" implies that we no longer think that way. I thought the imparfait makes no statement regarding whether something has stopped or not. Or have I misunderstood it?

I think the problem is that there is no imparfait in English. So we have to approximate when we deal with the French verbs. The approximations include were thinking, would think, used to think, or thought. None of those are exactly right, but we try to get as close as we can with each instance.

For me, the long term goal is to just understand the French imparfait on its own, or to really think in French. But I suppose that will not be easy....